The present invention relates to an enclosure having the ability to contain acoustical noise and, more specifically, to an enclosure for use with automatic business or typing machines, which isolates the high-frequency noise created by such machines.
Ever since business machines, such as typewriters and teletype machines and the like, have been introduced into the office environment attempts have been made at quieting these machines to reduce their intrusion into the office environment. Covers and cases have been devised with hinged tops and glass windows so that the office machine may be manipulated and viewed, while at the same time attempting to muffle the noise. Some cases have even been provided with ventilation fans so that the machine may operate without overheating.
Even though such cases and covers have been available for many years, at the present time there are no acoustical enclosures on the market which adequately isolate high-frequency noise. One of the reasons for this is that due to the advent of the modern high-speed printers and typewriters, the noises being produced are of a higher frequency than the old teletype or manual typewriter noise. Conventional enclosures are not sufficiently by designed so as to be capable of eliminating these undesired high-frequency noises. Additionally, the high-speed machinery of today produces mechanical vibrations, which also tend to interfere with the isolation efficiency of the acoustic enclosures.